Rare South Atlantic subtropical cyclone forms; severe weather season in U.S. underway

A rare weather event is underway in the South Atlantic Ocean, where the basin's 7th recorded tropical or subtropical cyclone of all-time has formed. An area of disturbed weather (Invest 90Q) off the coast of Brazil, near 30S 48W, attained a well-defined surface circulation, top wind speeds of tropical depression strength (35 mph), a warm core in the bottom portion of the atmosphere, and a cold core aloft last night. If this storm had been in the North Atlantic, there is a good chance it would have been named Subtropical Depression One. However, tropical and subtropical storms are so rare in the South Atlantic that there is no official naming of depressions or storms done. The cyclone had top winds of at least 35 mph as seen on an ASCAT pass at 7:02 am EST this morning (Figure 2), and satellite estimates of the storm's intensity topped out at 40 mph (minimum subtropical storms strength) last night. This morning, the satellite estimates are showing that the system has weakened to a 35 mph tropical depression. There is some moderate wind shear interfering with development, and sea surface temperatures are about 25°C, which is about 1°C below what is typically needed to support a tropical storm. The storm is headed eastward out to sea, and is not a threat to any land areas. The models show the storm will lose its tropical characteristics and get absorbed by a frontal system by Saturday.

Figure 2. Satellite-measured winds from ASCAT clearly show the circulation of the cyclone in this pass from 7:02 am EST on March 10, 2010. Top winds as seen be ASCAT were 30 knots (35 mph), just below the 40 mph needed for it to be a tropical storm. Image credit: NOAA/NESDIS/ORA.

Brazil has had only one landfalling tropical cyclone in its history, Cyclone Catarina of March 2004. Catarina is one of only six known tropical or subtropical cyclones to form in the South Atlantic, and the only one to reach hurricane strength. Tropical cyclones rarely form in the South Atlantic Ocean, due to strong upper-level wind shear, cool water temperatures, and the lack of an initial disturbance to get things spinning (no African waves or Intertropical Convergence Zone exist in the proper locations in the South Atlantic to help spawn tropical storms). Today's storm is located close to where Catarina formed.

Severe weather season beginsIt's March, and that means severe weather season will get underway in earnest for the Midwest U.S., and powerful spring storm systems draw warm, moist air from the Gulf of Mexico northward, to collide with cold, dry air from Canada. It's been a quiet early season, with only 42 tornadoes reported thus far this year (as of Sunday), compared to a normal 70 - 100 twisters. There was only one tornado in the U.S. in February, in a San Joaquin Valley oilfield in California two weekends ago. A year ago, there were 36 February tornadoes, and the year's deadliest tornado occurred on Feb. 10, 2009, in Lone Grove, Oklahoma, where eight people died in a storm with winds estimated at 170 mph. But thanks to a very wet winter and a continued active jet stream pattern that will pull strong storms through the Midwestern U.S. this month, expect at least an average March for severe weather. NOAA's Storm Prediction Center is forecasting a "slight" chance of severe weather across a large portion of the Mississippi Valley today, in association with a strong cold front that will be plowing through the region. Strong thuderstorms capable of generating damaging winds and large hail should develop along the front from southeast Kansas through eastern Oklahoma into NE Texas by middle/late afternoon. The storms should consolidate into broken bands and move into Missouri and and Arkansas by early evening. Isolated tornadoes are also possible in the entire "slight" risk area.

Hurricane Hugo talkI'm presenting a talk to a class at the University of Michigan this morning on my 1989 flight through Hurricane Hugo. You can listen in live starting at about 10:10 - 10:15 am EST by pointing your browser to http://samson.lecturetools.org/. You'll need to have Apple Quicktime installed. If all goes well, the talk will be recorded and you can view it later, as well.

A strong earthquake has occurred, but a tsunami IS NOT expected along the California, Oregon, Washington, British Columbia, or Alaska coast. NO tsunami warning, watch or advisory is in effect for these areas.

Based on the earthquake magnitude and historic tsunami records, a damaging tsunami IS NOT expected along the California, Oregon, Washington, British Columbia, and Alaska coasts. At coastal locations which have experienced strong ground shaking, local tsunamis are possible due to underwater landslides.

At 6:40 AM Pacific Standard Time on March 11, an earthquake with preliminary magnitude 7.2 occurred near the coast of central Chile . (Refer to the United States Geological Survey for official earthquake parameters.)

The Pacific Tsunami Warning Center in Ewa Beach, Hawaii will issue messages for Hawaii and other areas of the Pacific outside California, Oregon, Washington, British Columbia, and Alaska.

This will be the only statement issued for this event by the West Coast/Alaska Tsunami Warning Center unless conditions warrant. See the WCATWC web site for basic tsunami information, safety rules, and a tsunami travel time map and table. (NOTE: Travel time maps and tables indicate forecasted times only, not that a wave was generated.)USGS Link

The highest probablity of a severe wx outbreak for central and south FL w/be tomorrow morning thru early evening as a area of low pressure forms in the eastern GOM and moves ashore w/a strong jet stream over FL,I believe we could see a dozen+ tornado reports tomorrow and tornado watches are a 90% probabilty,IMO.....today severe wx should be isolated w/highest chance in NE FL

The air is very unstable. You can see how unstable it is by watching the storms actually form over land. Look how the storms are just forming on the east of Tampa Bay...

They lowered the Total amounts down from 2-3 inches to 1-2 for tomorrow.

They also took away the thunder storm icons for today and tomorrow.NWS Tampa

Today: Showers and possibly a thunderstorm. High near 72. South southwest wind between 16 and 22 mph, with gusts as high as 31 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

Tonight: Showers likely and possibly a thunderstorm. Cloudy, with a low around 66. South southwest wind between 7 and 9 mph. Chance of precipitation is 60%. New rainfall amounts between three quarters and one inch possible.

Friday: Showers and possibly a thunderstorm. High near 71. Southwest wind between 7 and 10 mph. Chance of precipitation is 80%. New rainfall amounts between 1 and 2 inches possible.

Good evening all, I have some sad news, I have stuffed up my pc and it loks as if I have lost all my weather links, I am so very upset. If anyone knows how to fix missing hal.dll file problem let me know.I am very down hearted, Aussie :-(

It is a little far fetched to give an exact number...but you can basically do it by using the analogs, and the parameters that are setting up. I personally like Bastardi. Those who have known me for a while, know how accurate I can be in hurricane forecasting. Who do you think I've studied for the past 3-4 years?

Bastardi generates excellent data, and is usually very good with his analysis. My issue with him (and accuweather as a whole) is the level of hype that is applied to storms and weather events. I can do without the hype, personally.

Quoting weathermanwannabe:Good Morning. Got up early to get to work in downtown Tallahassee to beat the rush. Plenty of rain in our parts this morning; gonna be a mess out there during the rush hour (as I sit here sipping my coffee...........)

Rush hour, funny, all ten minutes of it. I wish it was like that in the Tampa area.

Quoting Chicklit:FlWeatherFreak & 9641: What's interesting is the NWS has put out a warning but on Wunderground there is no severe weather threat:452 AM EST THU MAR 11 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

...THUNDERSTORM IMPACT...FORECAST SOUNDINGS ARE INDICATING THAT THERE SHOULD BE SUFFICIENT LOW LEVEL WIND SHEAR TO PRODUCE ROTATING STORMS DURING THE DAY.MID AND UPPER LEVEL SUPPORT WILL ALSO AID IN PRODUCING STRONG TO SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS. BECAUSE OF THE FORECAST STRENGTH OF THE LOW LEVEL WIND SHEAR...ANY SEVERE STORMS COULD ALSO SPAWN A TORNADO.

...FLOOD IMPACT...ALTHOUGH STORMS WILL BE MOVING FAST...INDIVIDUAL CELLS WITH HEAVIER RAIN REPEATEDLY PASSING OVER ANY GIVEN LOCATION COULD PRODUCE SHORT TERM ACCUMULATIONS OF WATER ON STREETS...LOW LYING AREAS AND THE LOW SPOTS UNDERNEATH BRIDGES.

...WATERSPOUT IMPACT...STRONGER STORMS MAY PRODUCE FUNNEL CLOUDS AND WATER SPOUTS OVER THE COASTAL WATERS. STORM MOVEMENT WILL BE TO THE NORTHEAST DURING THE DAY.

...WIND AND SEA IMPACT...STRONG SOUTHERLY WINDS WILL PRODUCE WINDS OF 20 TO 25 KNOTS OVER THE OFFSHORE WATERS THROUGH MID EVENING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.A LARGE AREA OF SHOWERS AND STORMS IS EXPECTED TO OVERSPREAD THE AREA ON FRIDAY. SOME STORMS COULD BE STRONG TO SEVERE AND MORE WIDESPREAD HEAVY RAIN IS EXPECTED.

GUSTY WEST WINDS WILL USHER IN DRIER AIR BEHIND A COLD FRONT EARLY SATURDAY. MARGINALLY HAZARDOUS BOATING CONDITIONS WILL OCCUR IN THE OPEN ATLANTIC OVER THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE REQUESTED TO MONITOR THE WEATHER AND SELF ACTIVATE IF NEEDED.$$ WIMMER/LASCODYAnd this is on Wunderground:Forecast for Coastal Volusia County

Updated: 3:40 am EST on March 11, 2010 No Active Advisories Severe Weather map does not include ECFL.

Its not showing on WU, since the NWS statement is just a discussion note, rather than a full-fledged watch or warning.

At 12:00 PM UTC, Tropical Depression 14 (999 hPa) located at 10.9S 175.5W has 10 minute sustained winds of 30 knots within 60 to 150 NM of center in sectors from northwest through northeast to southeast and southwest. Position POOR based on hourly GMS/GOES enhanced infrared imagery with animation. The depression is reported as moving west-southwest at 8 knots.

Organization improving steadily. Primary bands to east and west consolidating and beginning to wrap around low level circulation center. Deep convection developing about low level circulation center region. System lies in a diffluent environment. Sea surface temperature is around 30C. Outflow good to east and north, developing elsewhere. System steered west-southwest by northeast deep layer mean flow.

At 12:00 PM UTC, Overland Depression, Former Hubert (1000 hPa) located at 20.7S 47.5E has 10 minute sustained winds of 25 knots with gusts of 35 knots. The depression is reported as moving west-southwest at 3 knots.

Additional Information=======================Under the Malagasy highlands constraint, Former Cyclone Hubert will rapidly destructurate. Strongest winds do no exceed 20-25 knots anymore near the center with strong gusts under squalls. There still reach 25 knot locally 30 knots over the eastern Malagasy coastline. System should maintain a general westward then southwestward track on the northeastern edge of the subtropical high pressures. Therefore, it is expected to remain overland over the next 24 hours and go out overseas, with a very weakened circulation. If this happens, the potential for re-intensification appears to be poor due to increasing northwesterly shear. This forecast is based on the most available numerical weather prediction models.

LAST WARNING RELATED TO THIS SYSTEM UNLESS REGENERATION AS IT TRACKS BACK OVERSEA.

PepsiCo is raising prices on its Tropicana orange juice because of the deep freeze that hurt much of Florida’s citrus crop, the company said Wednesday. PepsiCo said it was shrinking its most popular size by about 8 percent, while maintaining its price, and raising the price on another size starting in May.

The 64-ounce container of orange juice will drop to 59 ounces. The suggested retail price will remain at $3.59.

The price of Tropicana’s gallon container of pure premium orange juice will rise from 5 percent to 8 percent. The suggested retail price now is $6.49. Link

Quoting FLWeatherFreak91: I doubt in the end that much severe weather will get going with today's storms. Although the jet is active over the area, cloud cover will keep temperatures limited which should suppress any chance for a severe storm.

72.5 °FOvercastHumidity: 81%Dew Point: 66 °F

We got a little sneak peak with the last system in CNTRL & SFL, juicy dew points and high RH should off set the cloud cover. Temps already approaching the mid 70's though, it's only 8:45am. The severe threat is supposed to diminish this morning and afternoon with an increased risk starting later this afternoon, evening and into tomorrow.

FlWeatherFreak & 9641: What's interesting is the NWS has put out a warning but on Wunderground there is no severe weather threat:452 AM EST THU MAR 11 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

...THUNDERSTORM IMPACT...FORECAST SOUNDINGS ARE INDICATING THAT THERE SHOULD BE SUFFICIENT LOW LEVEL WIND SHEAR TO PRODUCE ROTATING STORMS DURING THE DAY.MID AND UPPER LEVEL SUPPORT WILL ALSO AID IN PRODUCING STRONG TO SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS. BECAUSE OF THE FORECAST STRENGTH OF THE LOW LEVEL WIND SHEAR...ANY SEVERE STORMS COULD ALSO SPAWN A TORNADO.

...FLOOD IMPACT...ALTHOUGH STORMS WILL BE MOVING FAST...INDIVIDUAL CELLS WITH HEAVIER RAIN REPEATEDLY PASSING OVER ANY GIVEN LOCATION COULD PRODUCE SHORT TERM ACCUMULATIONS OF WATER ON STREETS...LOW LYING AREAS AND THE LOW SPOTS UNDERNEATH BRIDGES.

...WATERSPOUT IMPACT...STRONGER STORMS MAY PRODUCE FUNNEL CLOUDS AND WATER SPOUTS OVER THE COASTAL WATERS. STORM MOVEMENT WILL BE TO THE NORTHEAST DURING THE DAY.

...WIND AND SEA IMPACT...STRONG SOUTHERLY WINDS WILL PRODUCE WINDS OF 20 TO 25 KNOTS OVER THE OFFSHORE WATERS THROUGH MID EVENING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.A LARGE AREA OF SHOWERS AND STORMS IS EXPECTED TO OVERSPREAD THE AREA ON FRIDAY. SOME STORMS COULD BE STRONG TO SEVERE AND MORE WIDESPREAD HEAVY RAIN IS EXPECTED.

GUSTY WEST WINDS WILL USHER IN DRIER AIR BEHIND A COLD FRONT EARLY SATURDAY. MARGINALLY HAZARDOUS BOATING CONDITIONS WILL OCCUR IN THE OPEN ATLANTIC OVER THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE REQUESTED TO MONITOR THE WEATHER AND SELF ACTIVATE IF NEEDED.$$ WIMMER/LASCODYAnd this is on Wunderground:Forecast for Coastal Volusia County

Updated: 3:40 am EST on March 11, 2010 No Active Advisories Severe Weather map does not include ECFL.

Quoting Jeff9641:Severe wx expected in C FL today get ready because some of these storms could be big hail producers and possibly a tornado or 2.

I doubt in the end that much severe weather will get going with today's storms. Although the jet is active over the area, cloud cover will keep temperatures limited which should suppress any chance for a severe storm.

Quoting weathermanwannabe:Good Morning. Got up early to get to work in downtown Tallahassee to beat the rush. Plenty of rain in our parts this morning; gonna be a mess out there during the rush hour (as I sit here sipping my coffee...........)

Good Morning. Got up early to get to work in downtown Tallahassee to beat the rush. Plenty of rain in our parts this morning; gonna be a mess out there during the rush hour (as I sit here sipping my coffee...........)